[Samba] login problem as non-root

[Murat Can Tuna]

Hi,

I have an ubuntu server and Fedora 11 as client.Samba and Openldap is up 
to date.I successfuly log in to my samba accounts as root(without 
password prompt) but whenever I try to login as non-root, I get password 
incorrect error and secure log is as follow:

su: pam_unix(su:auth): authentication failure; logname=tuna uid=501 
euid=0 tty=pts/0 ruser=tuna rhost=  user=mrtcn

Oct  6 16:44:42 tiergartenstrasse su: pam_winbind(su:account): 
valid_user: wbcGetpwnam gave WBC_ERR_DOMAIN_NOT_FOUND

Oct  6 16:44:45 tiergartenstrasse su: pam_unix(su:auth): authentication 
failure; logname=tuna uid=501 euid=0 tty=pts/0 ruser=tuna rhost=  user=mrtcn

Oct  6 16:44:45 tiergartenstrasse su: pam_winbind(su:account): 
valid_user: wbcGetpwnam gave WBC_ERR_DOMAIN_NOT_FOUND

Oct  6 16:48:09 tiergartenstrasse su: pam_unix(su-l:session): session 
opened for user root by tuna(uid=501)

Do you have any idea what would be the problem? I just need some advises 
to search the problem on the right path. It seems like the problem is 
about pam configurations but on default introductions they don't say 
anything about pam that's why I didn't touch on pam configurations.

Thanks in Advance